Knitting machines



NOV- 30, 1965 F. H. cARRoTTE x-:TALv 3,220,222

KNITTING MACHINES Filed Oct. 9, 1962 2 Sheets-Sheet 1 Heder/df Hanf Caf/off@ Joh/7 Emes EMS By fha/'f @fio/nays Nov. 30, 1965 F. H. CARROTTE ETAL KNITTING MACHINES 2 Sheets-Sheet 2 Filed Oct. 9, 1962 FIG.2

, l h /m/@f//o/s Heder/ck Heng/Uf/O// ./0/7/7 Ernes/ E//AS 5y #1e/'r af/om @ys United States Patent Q 3,220,222 KNITTING MACHNES Frederick Henry Carrotte, Leicester, and `lohn Ernest Ellis, Queniborough, near Leicester, England, assignors to A. Kirkland and Company Limited, Leicester, England, a British company Filed Oct. 9, 1962, Ser. No. 229,376 Claims priority, application Great Britain, Oct. 11, 1961, 36,475/61 Claims. (Cl. 66-151) This invention relates to knitting machines of the circular type, and is concerned with fabric take-up mecha nism for such machines. The take-up mechanism usually comprises a pair of winding-down rollers between which the fabric is passed and which grip it to draw it down from the needles and, below the winding-down rollers, a take-up roller upon which the fabric is wound. The rollers are mounted transversely of the machine, and are usually driven by a follower engaging a cam ring, the cam ring, and the rollers and follower being mounted respectively on parts of the machine which have relative rotation when the machine is in motion. Thus in the case of rotating cylinder machines, the cam ring is mounted on the machine frame and the rollers and follower are mounted in a carriage which rotates with the cylinder and is carried in bearings in the frame. In the case of rotating dial case machines the rollers and follower are mounted on the machine frame and the ring is mounted to rotate With the dial case.

The cam is shaped so as to depress the follower and allow it to rise again in each rotation of the machine. The follower is usually mounted on an arm connected to a pawl engaging a ratchet wheel on one of the winding-down roller spindles so as to rotate the roller as the follower is depressed, the follower being returned by a spring, and reverse rotation of the roller is prevented by a second ratchet wheel engaging a springpressed pawl. The rollers are usually geared together for simultaneous rotation.

A similar system of cam follower and ratchet wheels is usually employed for rotating the take-up roller.

The cam is frequently simply a at circular ring which is pivotable about a diameter so as to vary its cam angle for altering the rate of fabric wind-down. Such a cam, however, does not give constant speed depression of the follower, so that the speed of rotation of the rollers is not constant and, moreover, winding is only intermittent, so that the fabric is not maintained under constant tension, leading to inefficient take-down and variation of the quality of the fabric knitted. Furthermore, pawls and ratchet wheels suffer from a degree of backlash and a small degree of reverse rotation of the rollers often occurs as the follower is being returned, removing the tension from the fabric and leading to similar difliculties.

According to the present invention a circular knitting machine having two parts which have relative rotation when the machine is in operation has a fabric take-up mechanism comprising a cam ring mounted on one of said parts, co-axially with the rotational axis and a pair of winding-down rollers mounted parallel to each other on the other of said parts, for drawing the fabric between them, a one-way clutch at each end of one of the rollers, having a driving member and a driven member, the driven members being drivingly connected to the respective ends of the said roller, a cam follower drivingly connected to each of the driving members, the two cam followers being positioned for engaging the cam surface of the cam ring at substantially diametrically opposite locations, the cam surface of the cam ring having a substantially constant cam angle with respect 3,220,222 Patented Nov. 30, 1965 "ice to a plane perpendicular to the rotational axis throughout a circumferential length at least equal to the major arc of the cam between the points of contact of the followers with the surface.

Further, according to the invention, fabric take-up mechanism for a circular knitting machine having two parts which have relative rotation when the machine is in operation comprises a cam ring mounted on one of said parts, co-axially with the rotational axis and a pair of winding-down rollers mounted parallel to each other on the other of said parts, for drawing the fabric between them, a one-way clutch at each end of one of the rollers, having a driving member and a driven member, the driven members being drivingly connected to the respective ends of the said roller, a cam follower drivingly connected to each of the driving members, the two cam followers being positioned for engaging the cam surface of the cam ring at substantially diametrically opposite locations, the cam surface of the cam ring having a substantially constant cam angle with respect to a plane perpendicular to the rotation axis throughout a circumferential length at least equal to the major arc of the cani between the points of contact of the followers with the surface.

The cam ring may be a closed loop, or may be gapped, extending only for the said circumferential length or a suitable amount beyond it to provide a lead-in for the cam followers.

With this arrangement each follower engages the operative part of the cam surface and its depression is commenced so that it takes up the drive of the roller before the other follower rides off the end of the operative part, so that the roller is rotated continuously, one of the clutches always being in the driving condition when the other is permitting its follower to return to the original position. Moreover, due to the constant cam angle the followers are depressed at a uniform speed as they traverse the operative part of the cam surface, so that they impart a substantially constant speed of rotation to the roller and the fabric is thus maintained continuously under substantially constant tension. To vary this speed of rotation the followers may be adjustably mounted on lever arms mounted on the driving members of the one-way clutches.

The one-way clutches may be of the ratchet type, but preferably are of the known kind comprising concentric driving and driven members having confronting spaced circular cylindrical faces between which are a number of rockable elements shaped so as to lie upon one of the faces so as to permit free rotation between the members in one direction-the free directionbut if relative rotation is commenced in the opposite direction the rockable elements rock so as to wedge between the members so as to lock the assembly for transmitting drive.

It will be understood that when the followers are mounted on lever arms, as described, for them both to impart rotation in the same direction to the roller their arms must both extend to the same side of the plane through the axis of the two clutches parallel to the axis of relative rotation between the cam and followers. Thus if the clutches are diametrically opposite to each other with respect to the ring, the followers will engage the ring at points which are not diametrically opposite, but may be a few degrees out from this condition.

The fabric take-up roller may be driven by a further follower engaging the same cam ring, and transmitting drive to the roller through a oneway clutch, reverse rotation of the roller being prevented by a second oneway clutch operating in the opposite direction. To allow for a differential rate of winding as the fabric roll grows a resilient lost-motion device is preferably incorporated in the mechanism transmitting drive to the takeup roller.

An embodiment of the invention is illustrated by way of example by the accompanying drawings in which:

FIGURE 1 is a fragmentary sectional elevation of a portion of a knitting machine taken along the line B-B of FIG. 2 and showing a one-way clutch at each end of a winding-down roller, and

FIGURE 2 is a fragmentary elevation viewed in the direction of arrow A of FIGURE 1.

The winding-down rollers 1 and the take-up roller 2 are mounted across the machine below the knitting cylinder (not shown) with a guide 3 above the rollers 1. The rollers 1 and 2 are mounted in a carriage 4 rotatable with the cylinder and carried on the machine frame 5 by bearings 6. Each winding-down roller 1 has at each end a gear 7, the gears at each and meshing with each oth-er. The gear 7 at each end of one of the pair of rollers 1 meshes with a gear 8 rotatably mounted on a spindle 9 in the carriage 4, the gears 3 and associated parts at each end of one of the rollers 1 being shown in the drawings. Formed integrally with each gear 8 is the inner member 10 of a one-way clutch of a known kind, see, for example, United States Patents 2,561,000; 2,883,023; and 2,892,523, in which the outer surface of the inner member, and the inner surface of the surrounding outer member 11, which, is also rotatable about the spindle 9, are circular cylindrical. Between the inner and outer members is a number of rockable elements 12 profiled so that when the relative rotation between the outer member and the inner member is in one directionthe free direction-they will lie upon the inner member so as to permit the members to rotate relative to each other, but if relative rotation is commenced in the opposite directionthe drive direction-the elements 12 rock so as to wedge between the members and lock the assembly for transmitting drive, or, if desired, for holding the assembly stationary.

Secured to the outer member 11 is an arm 13 having a number of equally spaced holes 14 in one of which is mounted a pin 15 engaging a slot 16 in a block 17 carrying a cam follower roller 18. It will be seen that the parts 8 to 18 are provided at each end of the carriage 4, so that there are two follower rollers 18 at approximately diametrically opposite positions with respect to the axis of rotation .of the carriage 4. Mounted on the machine frame 5 so as to be engaged by the follower 18 is a cam ring 19 the lower operative surface of which has a constant cam angle u with respect to the plane perpendicular to the axis of rotation of the carriage so that, during one revolution of the carriage 4, it causes a uniform rate of depression of the follower over about 230 and permits return of the follower under the inuence of a spring (not shown) over the remainder of the revolution. The ring may be a complete circle, or may only extend a little beyond the necessary 230, with suitable lead-in for the followers. On each side of the carriage the rockable elements 12 of the one-way clutches (l0-12) are arranged so that their drive direction is in the direction of rotation of the respective arm 13 when the follower 18 is depressed by the cam ring 19, and corresponds to winding down rotation of the rollers 1. In these clutches (l0-12) therefore, the outer members 11 constitute driving members, and the inner members 10 are driven, through the rockable members 12. The two followers 18 are approximately diametrically opposed with respect to the cam ring, although not exactly so since both arms must project to the same side of the vertical plane through the axis of the clutches in order to impart rotation in the same direction when depressed by the cam. Each follower will in turn engage the operative part of the cam surface, the 230 circumferential length of which is such as to exceed the major arc between the points of contact with the followers, before the other has left it, so that the rollers will be driven continuously. Due to the profiling of the cam surface their speed of rotation will be substantially constant, variation being caused only by the arcuate path of movement of the followers. To adjust this speed of rotation, the block 17, may be moved with respect to the pin 15 by virtue of its slot 16, which is of length equal to the pitch of the holes 14. For greater adjustment, the pin 15 may be removed and inserted in a different hole 14. Thus the effective length of the arm may be varied as desired. The position of the follower thus gives a deftnite indication of the rate of winding down, and to facilitate setting this rate scale calibrations 34 may be marked on the arm 13, and the block 17 may carry a pointer 35. The arm is curved complementarily to the cam ring so that the follower will engage it when mounted in any of its positions.

The fabric can thus be wound down continuously, at substantially constant speed, and therefore substantially constant tension, leading to consistency of quality.

rThe fabric take-up roller 2 is removably carried between mounts 20, 21. The mount 21 comprises a rotatable spindle having secured to it the inner members of a pair of one-way clutches 36 and 37 similar to that described above. The numeral 40 designates an expanding coil spring used to actuate the rockable elements of the one-way clutches. The outer member 22 of one of these clutches is secured to the carriage 4, and its rockable elements (not shown) are arranged to lock when the inner member tends to rotate in the direction opposite to take-up of the fabric, thus preventing unwinding of the fabric. The rockable elements 39 of the other clutch 37 are arranged in the opposite manner, and the outer member 23 of this clutch has mounted on it a plate 24 connected by a resilient link shown generally by 41 to an arm 25 conveniently pivoted on the member 11 and carrying a follower roller 26 arranged so as to engage the cam ring 19. As the carriage 4 rotates the follower roller 26 is depressed by the cam ring, so causing the outer member 23 to rotate in the direction corresponding to take-up of the fabric. This rotation is transmitted through the rockable elements 39 and inner member 38 of the one-way clutch 37 to the roller 2 which thus winds the fabric.

The resilient link 41 is provided to maintain the winding tension of the roll of fabric substantially constant as the roll increases in diameter, and comprises an end member 27 connected to the arm 25 and having secured to it a screw threaded rod 28 the end of which is slidably anchored in a second end member 29 connected to the plate 24. An abutment nut 30 engages the screw threaded rod 28 and has secured to it a sleeve 31. Within the sleeve, surrounding the `rod 28, and between the abutment nut 3) and the end member 29, is a compression spring 32. When the follower roller 26 is depressed its initial movement causes rotation of the roller 2, as described, but when the tension in the fabric overcomes the initial compression of the spring 32, the rod 28 slides in the member 29 and the spring is further compressed. By `turning the sleeve 31 the initial compression of the spring 32 can be varied so as to adjust the tension with which the fabric is wound. To assist in setting this tension the end member 29 may carry scale calibrations 33 by which the position of the sleeve 31 may be set` A tensioning spring 34 connected between the plate 24 and the carriage 4 serves to hold the follower roller 26 in firm contact with the cam ring 19.

What we claim is:

1. A circular knitting machine having two parts with relative rotation when the machine is in operation, in which there is a fabric take-up mechanism, the machine having a cam ring mounted on one of the two parts having relative rotation, said cam ring being coaxial with the rotational axis of the machine,

a pair of winding-down rollers for drawing the fabric between them mounted parallel to each other on the other of the two machine parts having relative rotation,

in combination with a one-way clutch at each end of one of said rollers, each clutch having a driving member and a driven member, the driven members being drivingly connected to the respective ends of such roller of the pair,

a cam follower drivingly connected to each one of said driving members, the two cam followers being positioned for engaging the cam surface of the cam ring at substantially opposite locations,

the cam surface of the cam ring having a substantially constant angle with respect to a plane perpendicular to the rotational axis of the machine throughout a circumferential length at least equal to the major arc of the cam between the points of contact of the followers with the cam surface.

2. Fabric take-up mechanism for a circular knitting machine having two parts with rotation relative therebetween,

comprising a cam ring mounted on one of the two parts having relative rotation, said cam ring being coaxial with the rotational axis of the machine,

a pair of winding down rollers for drawing the fabric between them, mounted parallel to each other on the other of the two machine parts having relative rotation,

in combination with a one-way clutch at each end of one of said rollers, each clutch having a driving member and a driven member, the driven members being drivingly connected to the respective ends of such roller of the pair,

a cam follower drivingly connected to each one of said driving members, the two cam followers being positioned for engaging the cam surface of the cam ring at substantially opposite locations,

the cam surface of the cam ring having a substantially constant angle with respect to a plane perpendicular to the rotational axis of the machine throughout a circumferential length at least equal to the major arc of the cam between the points of contact of the followers with the cam surface.

3. Fabric take-up mechanism according to claim 2 in which the two parts of the machine having rotation relative to each other are a machine frame and a carriage rotatable with the knitting cylinder of the machine.

4. Fabric take-up mechanism according to claim 3 wherein the cam ring is mounted on the machine frame and the rollers are mounted on the carriage.

S. Fabric take-up mechanism according to claim 2 in which the one-way clutches are mounted on that relatively rotating part other than the cam ring bearing part, interengaging gears on the ends of the winding-down rollers and the respective driven members providing the driving connection therebetween.

6. Fabric take-up mechanism according to claim 2 having interengaging gears mounted respectively on one pair of adjacent ends of the winding-down rollers.

7. Fabric take-up mechanism according to claim 2 having a take-up roller mounted parallel to the windingdown rollers on the same machine part for taking-up fabric drawn by the winding-down rollers, a one-Way clutch at the end of the take-up roller, having a driven member drivingly connected to the take-up roller and a driving member, a further cam follower mounted on the said machine part to engage the cam surface and drivingly connected to the driving member.

8. Fabric take-up mechanism according to claim 7 including a resilient lost motion device providing driving connection between the further cam follower and the clutch at the end of the take-up roller.

9. Fabric take-up mechanism according to claim 8 wherein the resilient lost motion device is adjustable.

10. Fabric take-up mechanism according to claim 2 having lever arms mounted on the driving members of the one-way clutches and carrying the respective cam followers, the position of each cam follower on its lever arm being adjustable.

References Cited by the Examiner UNITED STATES PATENTS 582,452 5/1897 Brewin 66-153 1,870,879 8/1932 Swinglehurst 66-151 1,956,638 5/1934 Bromley et al 66-153 2,158,177 5/l939 Firsching 66-151 2,280,472 4/ 1942 Bromley et al 66-153 2,870,618 1/1959 Zeruneith 66-152 FOREIGN PATENTS 659,510 5/ 1938 Germany. 582,927 12/ 1946 Great Britain.

RUSSELL C. MADER, Primary Examiner.

DONALD W. PARKER, Examiner. 

1. A CIRCULAR KNITTING MACHINE HAVING TWO PARTS WITH RELATIVE ROTATION WHEN THE MACHINE IS IN OPERATION, IN WHICH THERE IS A FABRIC TAKE-UP MECHANISM, THE MACHINE HAVING A CAM RING MOUNTED ON ONE OF THE TWO PARTS HAVING RELATIVE ROTATION, SAID SAID CAM RING BEING COAXIAL WITH THE ROTATIONAL AXIS OF THE MACHINE, A PAIR OF WINDING-DOWN ROLLERS FOR DRAWING THE FABRIC BETWEEN THEM MOUNTED PARALLEL TO EACH OTHER ON THE OTHER OF THE TWO MACHINE PARTS HAVING RELATIVE ROTATION, IN COMBINATION WITH A ONE-WAY CLUTCH AT EACH END OF ONE OF SAID ROLLERS, EACH CLUTCH HAVING A DRIVING MEMBER AND A DRIVEN MEMBER, THE DRIVEN MEMBERS BEING DRIVINGLY CONNECTED TO THE RESPECCTIVE ENDS OF SUCH ROLLER OF THE PAIR, A CAM FOLLOWER DRIVINGLY CONNECTED TO EACH ONE OF SAID DRIVING MEMBERS, THE TWO CAM FOLLOWERS BEING POSITIONED FOR ENGAGING THE CAM SURFACE OF THE CAM RING AT SUBSTANTIALLY OPPOSITE LOCATIONS, THE CAM SURFACE OF THE CAM RING HAVING A SUBSTANTIALLY CONSTANT ANGLE WITH RESPECT TO A PLANE PERPENDICULAR TO THE ROTATIONAL AXIS OF THE MACHINE THROUGHOUT A CIRCUMFERENTIAL LENGTH AT LEAST EQUAL TO THE MAJOR ARC OF THE CAM BETWEEN THE POINTS OF CONTACT OF THE FOLLOWERS WITH THE CAM SURFACE. 